Arachnida in which the
prosoma is uniform and bears two median and six or ten lateral eyes and
the opisthosoma is divisible into mesosoma and metasoma, each of six
somites.
Pedicle absent; telson in the form of a poison-sting. Chelicerae of three
segments, small, chelate. Pedipalpi of six segments, large, powerful,
chelate (pincerlike). Legs of seven segments, tarsi with three claws.
Sternum triangular or pentagonal. Second mesosomatic somite bears a pair
of characteristic pectines. Respiration by four pairs of lung-books on
third to sixth opisthosomatic somites. Size: 14-210mm; ovoviparous;
earliest fossil records from Silurian; widespread in tropical and
subtropical regions. About 1300 species described.

1.
Sternum langer dan of even lang als
breed.............................................3
1. Sternum longer than or as long as
broad.................................................3Niet zo - Not
so.............................................................................................2

5.
Drie of vijf zijogen aan elke
kant..............................................................75. Three or five
lateral eyes on each
side...................................................7Niet zo - Not
so.............................................................................................6

1. Met een duidelijke
stekel of tubercel onder de
gifstekel.......................................DIPLOCENTRINAE
1. With an obvious spine or tubercle under the
sting.................................................DIPLOCENTRINAE2. Niet zo - Not
so.............................................................................................3

2.
De eerste vier staartsomieten zonder richel of met twee richels; lager
vlak effen..............................................3
2. First four somites of tail with no ridge or with two ridges; lower
surface smooth.................................................3Niet zo - Not
so.............................................................................................1